Pros
Fantastic at getting clearances crossed over. Generally hires at competitive salary rates especially if you are good at negotiating salary. If you are working as an overhead employee and "not" direct on contract - depending on your manager/supervisor - they can be great at providing training - up to around $5000/year. If you are in a position where you can work from home, they are pretty good about giving flexibility to do that on occassion - for instance, during the Jan 2010 snowstorm there were a LOT of employees (normal SAIC overhead employees) working from home.
Cons
Downside - if you are direct on contract (meaning, essentially the people pulling in the money for SAIC) it depends on your contract and program manager for training, etc. Forget working from home if your work is primarily in a secure environment. Many at the customer site are still trying to make up work on the weekends and nights from the snowstorm when we "wanted" to work but the gov buildings were shut down. Training direct on contract - unless it is in your contract that government will provide it - seems to completely be nonexistent on at least some contracts. Forget training. For education training - the $5000 they say they provide, you have to pay for it yourself first and it's understood that if everyone took advantage of it they couldn't provide it. HUGE discrepancy for those on contract. All those SAIC policies and guidances, individual development plans, etc.? it's a different beast and you need not worry about consistency. Not impressed by a long shot.